Stocking Up on Tamiflu Won't Guarantee Taming of the Flu
By Jenny Lim
SAN MATEO, Feb. 16- If an avian flu pandemic breaks out in the United States next fiscal year, chances are slim you'll get your hands on the antiviral drug, Tamiflu.
Governor Arnold Schwarzenegger's proposed state budget includes $1.5 million to purchase 200,000 doses of the medication. California has 35.8 million residents, according to the U.S. Census Bureau.
The federal government has 5.2 million courses of Tamiflu stockpiled, said Michael Earls of Trust for America's Health, a non-partisan health policy research organization in Washington, D.C. But to prepare for a pandemic, the National Vaccine Advisory Committee recommends a minimum federal stockpile of 40 million courses of an antiviral - primarily oseltamivir, or Tamiflu.
The World Health Organization's Web site reports the sole pharmaceutical manufacturer of Tamiflu would need a decade to produce enough of the antiviral to treat 20 percent of the world's population.
Worried? There may be little reason to fret. While Tamiflu has effectively treated some bird flu patients in Southeast Asia, there's no guarantee it will work against a mutated H5N1 virus, anyway. The proposed federal and state budgets include funding to buy Tamiflu, but it's not a magic pill.
Tamiflu does not get rid of influenza, but attacks the flu virus and lessens the severity of flu symptoms, said Brian Zamora, public health director for San Mateo County. The oral drug, also known as oseltamivir phosphate, is produced by the Swiss pharmaceutical company Roche Holding AG and has been used to treat the common flu. It is not a vaccine.
Instead, Tamiflu belongs to a class of medications called neuraminidase inhibitors, which stop flu viruses from spreading inside the body, according to the Roche Web site.
There is no way of knowing if Tamiflu could successfully treat bird flu infections during a pandemic, since it's unclear how a mutated H5N1 virus will behave, Zamora said.
The bird flu is capturing scientists and governments' attention because most humans have never been exposed to the avian strain of influenza. While many have been introduced to the H3N2 strain - the common flu - most people have no immunity against the H5N1 virus.
As a result, a worldwide outbreak would begin if H5N1 were to mutate into a form that could be spread from person to person, according to the Centers for Disease Control Web site. It's unknown whether Tamiflu would work against that altered avian flu strain.
"Clearly, there's a misperception of what Tamiflu does and doesn't do," Zamora said. "There's a lot of energy around this product, but it's really kind of an open question whether it's going to be helpful."
The California and U.S. proposed budgets emphasize readiness more than treatment of bird flu. Schwarzenegger's budget puts $1.5 million towards antiviral and vaccine purchases, while allotting $32 million to fund pandemic readiness programs. Suggested preparedness efforts include partially funding local health department pandemic flu plans and public information campaigns on avian flu.
A document describing highlights of the California Department of Health Services' budget reports the governor's plan includes money to buy 70,500 doses of Tamiflu in the current fiscal year "for an initial ring containment of avian influenza."
According to a Feb. 1, 2006 Tamiflu Factsheet released by Roche, the company will charge developed nations 15 euros, or $17.78, for one course of 10 Tamiflu capsules. Developing nations will pay 12 euros, or $14.22, per course.
While a vaccine will be the most effective medication to combat avian flu, an antiviral will be needed during the six to nine months it will take scientists to develop a vaccine, said TFAH's Earls. He co-authored "Ready or Not," the organization's 2005 study on the nation's readiness for public health emergencies.
In Nov. 2005, President George W. Bush requested emergency funding for a $7.1 billion, three-year strategic plan to prepare for a pandemic influenza outbreak in the United States. Last year, Congress put $3.3 billion towards the plan.
The president's suggested fiscal 2007 budget asks for another $2.3 billion for the pandemic flu plan, including $361 million to acquire enough antiviral courses to treat 20 million people.
Earls said the administration should be complemented for taking preemptive steps to address the pandemic. But he criticized the suggested budget for only funding a quarter of the states' purchases of antiviral drugs. That means state governments must buy 75 percent of the antivirals they need, and some states will not be able to handle that financial burden, Earls said.
In his Nov. 3, 2005 testimony to the Senate appropriations committee, Lowell Weicker, TFAH board president and former U.S. senator and Connecticut governor, said relying on states to pay for the bulk of their antiviral medications would amount "to an unfunded mandate to the tune of $510 million."
Another problem with budgeting for Tamiflu is that "we're not sure how much Tamiflu would be needed," Earls said.
Scientists are concerned successful treatment may require more Tamiflu per person than originally perceived, according to Earls. "It may take more than one dose to actually be effective," he said. In that case, the nation and states' stockpiles might not cover the 25 percent of the population they originally expected to protect, Earls said.
But even though there is no guarantee the antiviral will work against bird flu, it is still better to have some in stock, according to Zamora. "We need to make that investment," he said.
A medication other than Tamiflu may hit the market by the time an antiviral is needed, according to Zamora. San Mateo County has some antivirals already stockpiled, as part of ongoing bioterrorism preparedness plans, Zamora said. He could not specify the type or amount of antivirals in the county's stock.
On Jan. 14, the Centers for Disease Control encouraged doctors to use Tamiflu and another antiviral, Relenza, to treat the H3N2 strain of seasonal influenza. The order was issued because the current flu virus has become resistant to antiviral medications commonly prescribed to treat the common flu. The result: doctors are dissuading people from hoarding Tamiflu because it is now needed to treat the common flu.
According to a Public Policy Institute of California survey on the state budget, 49 percent of Californians are confident the U.S. government can handle an avian flu pandemic, while 47 percent are not. The Jan. 26 survey also found 72 percent of Californians are not worried they or their family members could catch the virus. The PPIC polled 2003 adults for the survey, with a +/- 2 percent sampling error.
Contact Jenny Lim at jennylim@stanford.edu
